Shane Gillis performs onstage at the 2019 Clusterfest on June 21, 2019 in San Francisco, California.Jeff Kravitz | FilmMagic, Inc | Getty ImagesFour days after it was announced that Shane Gillis would join the cast of “Saturday Night Live” for the show’s 45th season, Gillis was fired.The backlash came quick after a clip of the comedian using racial and homophobic slurs during an episode of his podcast from 2018 resurfaced. The video and all other content from the YouTube channel “Matt and Shane’s Secret Podcast” has been deleted.Many questioned how Gillis was hired in the first place. Hadn’t NBC gone through a hiring process, glanced through his previous material and fully vetted him before bringing him on board?Professional head hunters told CNBC that, yes, NBC could have done a better job in researching its potential job candidate before hiring him, but also cautioned that social media makes the vetting process much tougher.A NBC spokesperson said in a statement on behalf of “SNL” executive producer Lorne Michaels that they had not been aware of Gillis’ comments prior to hiring him and their “vetting process was not up to our standard.”The statement called Gillis’ language “offensive, hurtful and unacceptable.” Gillis responded to backlash last week saying, “I’m a comedian who pushes boundaries. I sometimes miss … I’m happy to apologize to anyone who’s actually offended by anything I’ve said. My intention is never to hurt anyone but I am trying to be the best comedian I can be and sometimes that requires risks.”Gillis made his first public appearance on Wednesday to a crowd at the Stand, a comedy club in New York City. During his set, he didn’t shy away from talking about his recent career turn.”I’m fine with the consequences,” he said during the set, according to Variety. “I’m not arguing. F— it. But I do want everyone to know that I’ve been reading every one of my death threats in an Asian accent.”The punch lineSome comedians have come out in defense of Gillis, claiming that people have become too sensitive and criticized SNL for firing the young comedian. Others argue that the firing of Gillis was less about folding to political correctness and more about how Gillis would fit into the culture of SNL.Sources told Variety that Gillis was actually hired in an attempt to appeal to more conservative viewers. The variety show has long been criticized for leaning to the left of center, often targeting Republicans more so than Democrats in its political sketches.”SNL” typically recruits new cast members from improv troupes like The Groundlings, The Second City, and The Upright Citizens Brigade. Gillis was not part of a group like this and does not have any credited onscreen acting experience, so it is likely he auditioned using a portion of his stand up routine.However, it’s not Gillis’ stand up material that landed him in hot water. It was his podcast. In one clip that surfaced on Twitter, Gillis and co-host Matt McCusker are talking about Chinatown. While Gillis is the only one to use a racial slur to describe people of Asian decent, both make fun of Asian accents by replacing “L” sounds with “R” sounds.And that’s not the only clip that resurfaced. In a now-deleted video Gillis and McCusker are discussing an online article about top up-and-coming comics and they grouse it doesn’t include a single white male, but has “four white chicks.”Gillis and McCusker agree that there is a pyramid of who is funny and who is not. White chicks are “literally at the bottom,” just below “gay dudes,” they said.Not only has SNL just hired its first Asian-American cast member, Bowen Yang, but this newcomer also happens to be gay. And then there is the massive list of female comedians that make up the veteran cast of the show. Bringing a new employee into the mix who has used racial slurs against Asians and opined that women are “unfunny” might not go over so well with a cast chock-full of women and people of diverse backgrounds.”You can’t paint a future employer into a corner like that,” said Jason Hanold, a managing partner at Hanold Associates. NBC had “no responsible choice than to do what they had done.”The vetting processIn the era of social media, hiring managers have expanded from just interviewing candidates for positions to scrolling through their Twitter, Instagram and Facebook to get a better sense of their potential future employee.”It has become increasingly more prevalent for companies to mine information on prospective employees,” Eric Fehr, vice president of operations, at Search Solution Group, a headhunting agency, said. “Job seekers, and especially students and young professionals, should be aware that anything they say or do online will possibly have long-lasting consequences.”For many companies, including here at CNBC, social media can be a place where employers get a clearer picture of the person who will walk in the door on their first day at the job. So, it’s not uncommon for them to scroll back through months, if not years, of posts looking for red flags.It is unclear what NBC’s process for hiring at SNL was. The company did not respond to CNBC’s request for comment.”If you are fundamentally a performer, that should have been part of the collateral review,” Hanold said. “You have an audition, but don’t you want to see how they perform in different circumstances?”It’s unclear when the videos on the “Matt and Shane’s Secret Podcast” YouTube channel were deleted. So, it’s possible they were not available to be viewed by NBC prior to Gillis’ hiring. However, some audio from past podcasts are still available online.”Different companies have different policies,” Josh Mangum, senior director of corporate strategy at Search Solution Group, said. “Some might look a little harder than others. But, it’s not something that comes up in a background check. You may have to comb through 10 hours worth of content or more.”Mangum said that the average person has five days worth of video uploaded online and that entertainers tend to have exponentially more.”I don’t really fault the company that hires people for SNL or the casting agents,” he said. “They can only do so much.”Dennis Theodorou, managing director at JMJ Phillip, a recruiting and executive search firm, said that companies have a lot of resources when it comes to looking into the background of future employees. They can hire an outside firm whose sole job is to vet new talent or even institute policies like a uniform interview process or personality tests.”On the recruitment side, we do that for our clients,” he said. “We don’t want to send someone to them that we’ve head hunted for them and have [the client] find something on the net [about a future employee] before we do.”Past offendersGillis is by no means the first comedian or entertainer to face backlash for past offensive comments.Trevor Noah, the host of Comedy Central’s “The Daily Show,” was criticized in 2018 after tweets from 2013 resurfaced and were deemed anti-Semitic and offensive towards aboriginal women.Noah responded on Twitter, “You’re right. After visiting Australia’s Bunjilaka museum and learning about aboriginal history first hand I vowed never to make a joke like that again. And I haven’t. I’ll make sure the clip from 2013 is not promoted in any way.”He was able to keep his job on the show.When it was announced in December that Kevin Hart would host the Oscars, a number of homophobic tweets he had posted between 2009 and 2011 reappeared online. Hart responded days later on Instagram, saying he declined to apologize for the tweets because he had already done so several years earlier.Hart said the Academy reached out to him and asked him to apologize or they would have to replace him as the host.”I chose to pass. I passed on the apology,” he said in a Instagram video. “The reason that I passed is because I have addressed this several times. This is not the first time this has come up, I have addressed it. I’ve spoken on it. I’ve said where the rights and wrongs were. I’ve said who I am now versus who I was then. I’ve done it. I’ve done it. I’m not going to continue to go back and tap into the days of old when I’ve moved on and I am in a completely different space in my life.”Hart had addressed his gay jokes in 2015 in his cover piece with Rolling Stone and in interviews for his movie “Get Hard.” Ultimately, Hart stepped down from the gig.Director James Gunn was fired from “Guardians of the Galaxy 3” in July 2018 after tweets from 2009 featuring offensive jokes about young boys were dredged up. He immediately apologized on Twitter in a five-part post. He had also previously apologized for these jokes in 2012.Shortly after, the cast of “Guardians of the Galaxy” wrote an open letter in support of Gunn, asking for hime to be brought back to the director’s chair for the third installment in the series. In March 2019 Gunn was reinstated.Theodorou said it matters how much time has gone by since the words were spoken or written.”Especially with everything going on right now, eight months ago is harder to forgive than 10 years ago,” he said.Disclosure: Comcast is the parent company of NBCUniversal and CNBC.